1. Field of the Invention
The present invention generally relates to a lubrication structure for a bearing section of an internal combustion engine and, more particularly, to a lubrication structure for a bearing section using a simple oil supplying device.
2. Description of Related Art
An internal combustion engine for a motorcycle wherein a breather plate, which configures a breather by being attached to an inner wall of a crankcase on the speed change gear accommodation side, is utilized such that a retainer section (bearing restriction section) for preventing a bearing from coming off, which bearing supporting a countershaft of a speed change gear, is provided at a portion of the breather plate. Such a internal combustion engine structure is disclosed in Japanese Patent No. 3060628.
In the internal combustion engine disclosed in Japanese Patent No. 3060628, a lower portion of the crankcase serves as an oil reserve chamber, and part of the speed change gear is lubricated by being dipped in oil or the oil is agitated or the like by the gear wheels or the like to lubricate the inside of the crankcase. However, since the countershaft and the bearing described above are exposed upwardly from the oil level, a device for supplying oil to the bearing is required. However, if it is intended to specially provide an oil supply device, then there is the possibility that the structure may be complicated and the number of parts may increase.